Direct conversion of thermal energy to electrical energy is facilitated by the
Fuel cells
Photo voltaic cell
Magneto hydrodynamic generator
None of these
Correct Answer :
C. Magneto hydrodynamic generator
Related Questions
Coarse grained steels have
Low toughness
No tendency to distort
High density
Very high toughness
About __________ ton of coke is required in a cupola to produce one ton of casting.
0.03
0.3
0.8
1.5
The yield point phenomenon observed in annealed low carbon steel is due to the presence of the following element.
Silicon
Carbon
Phosphorous
Chromium
Fibrous fracture is normally encountered in the __________ materials.
Hard
Elastic
Ductile
Brittle
The activity of pure hydrogen gas at 1000°C and 5 atm pressure
Is always less than 1
Is always greater than 1
Can be 5
Depends on the choice of the standard state
A thin, flat & square plate measuring 2 m × 2 m is freely hanging in ambient air at 25°C. It is exposed to the solar radiation falling on one side of the plate at the rate of 500 W/m2. The plate temperature will remain constant at 30°C, if the convective heat transfer co-efficient is __________ W/m2 °C.
50
100
150
200
Dryness fraction of dry steam is
0
∞
1
0.5
Pick out the wrong statement.
A soft magnetic material should have high permeability and small area of hysteresis loop
Poisson's ratio of high melting point metals is more than unity
Solders generally melt at less than 185°C
Steel produced by B.O.F process is ideally suited for manufacturing flat product
Which of the following materials does not form adherent oxide film on surface?
Copper
Nickel
Aluminium
Gold & silver
Which of the following has the highest value of refractive index?
Brine (sea water)
Diamond
Distilled water
Glass
A material being tested for endurance strength is subjected to the __________ load.
Impact
Completely reversed
Dynamic
Static & dynamic
Pick out the wrong statement.
Weldability of high carbon steel is poorer compared to low carbon steel
Invar is a magnetic alloy
Magnetic permeability of the diamagnetic material is less than one
Martenistic transformation never goes to completion (i.e., 100%) at room temperature
Pick out the wrong statement.
Cold cracking of a weld is due to the presence of hydrogen gas in the weld
True stress is given by, σ = σE (1 + εE), where σE and εE are engineering stress and engineering strain respectively
Phosphorous can be easily recovered in the iron blast furnace
High residual stress at the surface is beneficial for fatigue properties of a material
Cupola produces __________ iron.
Pig
Cast
Wrought
Carbon free
A dense structure of grinding wheel is not used for the
Ductile material
Hard materials
Brittle materials
Finishing cuts
Boiler tube size is specified by its thickness and __________ diameter.
Outside
Inside
Mean
None of these
Air/fuel ratio by weight for combustion of methane with theoretical quantity of air will be about
9 : 1
17 : 1
23 : 1
29 : 1
Wrought iron is never shaped by
Casting
Cold working
Forging
Welding
Which of the following are made out of the carbon steel having carbon content of 0.9 to 1%?
Small punches, broaches reamers and springs
Cutlery, screws, rivets and files
Mandrels, twist drills, small lathe tools and razors
Forgings like can shaft, structural steel plate, threading dies and drawing dies
Out of the following, the alloy which has equal percentage of constituents, is
White metal
Gun metal
Duralumin
Constantan
Thermal efficiency of an internal combustion engine is around __________ percent.
8
35
65
80
Nuclear fission of one atom of uranium-235 produces the energy equivalent to about __________ MeV.
20
200
500
2000
Removal of non-condensable from steam or other vapour is termed as the __________ process.
Condensation
Deaeration
Scavenging
Exhaust
Wrought iron is not
Ductile & resistant to corrosion/rusting
Weldable easily
Having uniform strength in all directions
Having maximum tensile strength along the lines of slag distribution
Pick out the wrong statement
Processing of thermosetting plastics is ideally done by injection moulding
Processing of thermoplastics is ideally done by compression moulding
Mass production of seamless pipes are done by electrical resistance welding (ERW)
Stretch forming is a process of cold drawing
With increase in annealing temperature, the following defect density decreases.
Vacancy
Dislocation
Grain boundary
All of these
Basicity 
of the slag in Indian blast furnace is in the range of
0.7-1.0
1.1-1.4
1.5 - 1.8
2.0 - 2.5
With increase in temperature, the electrical conductivity of a __________ decreases.
Semi-conductor
Metal or alloy
Dielectric
None of these
A form of stress corrosion failure termed as 'season cracking' is generally observed in
Thermosetting polymers
High carbon steels
Brasses
Borosilicate glasses
Dislocation cross-slip is difficult in those materials, which have
Large number of slip systems
High work hardening rate
Coarse grain size
Low stacking fault energy